(1) Field of the Invention
This invention relates to orthodontic arch wires and retainers (32/14).
(2) Description of the Prior Art
As the term "appliances" is used throughout this paper, it is meant to include not only the metal arch wires but all appliances of similar nature made from other materials such as plastic, Fiberglas, alloys, synthetic resins, etc., and also other shapes rather than the traditional cross-section as well as devices to retain or position the teeth after they have been moved.
Use of appliances such as arch wires positioners and retainers in orthodontics is well known. This is shown among other things, by the establishment of a sub class in the U.S. Patent and Trademark Office, Class 32-Densitry, Sub Class 14A-Orthodontic Devices; Band Brackets and Arch Wires.
Details of the technique of bending the arch wire to an arch form is particularly set out by Strang in his textbook of Orthodontia (Lea & Febiger, 3rd Ed., Philadelphia 1950) particularly on pages 661-671. He also describes the method of drawing Bonwill-Hawley diagrams or arch forms on pages 658-661. Other standard curves, which are recognized as arch forms for arch wires, are:
1. the Parabola from Sicher, H.: Oral Anatomy; 5th Ed., St. Louis, 1970, The C. V. Mosby Co., P. 262;
2. the Ellipse from Brader, A. C.: American Journal of Orthodontics, Volume 61, Number 6, 1972, pages 541-561;
3. the Catenary from MacConnail, M. M.: The Ideal Form of the Human Dental Arcade, With Some Prosthetic Applications, Dent. Rec., 69: 285-302, 1949; and Scott, J. H.: The Shape of the Dental Arches, Jour. Dent. Res. 36: 996-1003, 1957; also
4. the Two Parameter Catenary (Rocky Mountain Data Systems, See Data-Bits, Profiles From RMDS, Number 10).
Positioners made of plastic or rubber material are on the market by at least two companies: OrthoTain and T. P. Laboratories.
Before this application was filed, a search was made in the U.S. Patent and Trademark Office and the following patents were reported on that search:
______________________________________ 3,775,850 Northcutt 3,835,539 Wallshein 3,842,503 Wildman 3,879,849 Schwartz 3,906,634 Aspel 4,014,096 Dellinger ______________________________________
Applicant does not believe that these references are as pertinent as the publications specifically discussed above.